Uploaded November 2010 | Updated September 2026, 1 hour ago
I finally downloaded OpenCV (an open source computer vision library) and spent some time learning about how to use it. It was actually surprisingly painless once I got the hang of it, and there are lots of things you can do once you feed it an image (in this case, the depth image). What I did was rig it to track contours on the depth image, and attempt to pick out a rectangular object.
Then, by using the detected location of the corners, I can apply it as a perspective transform to my laser projector. The end result is that the cardboard box I'm holding becomes a "virtual screen" that is tracked by the laser projection in real time and in perspective :)
I finally downloaded OpenCV (an open source computer vision library) and spent some time learning about how to use it. It was actually surprisingly painless once I got the hang of it, and there are lots of things you can do once you feed it an image (in this case, the depth image). What I did was rig it to track contours on the depth image, and attempt to pick out a rectangular object.
Then, by using the detected location of the corners, I can apply it as a perspective transform to my laser projector. The end result is that the cardboard box I'm holding becomes a "virtual screen" that is tracked by the laser projection in real time and in perspective :)
![sisters noise - Toaru Kagaku no Railgun S / fripSide [piano]](https://i.ytimg.com/vi/QTPvvrH5gxs/mqdefault.jpg "sisters noise - Toaru Kagaku no Railgun S / fripSide [piano]
I finally convinced myself to upload another arrangement! I should probably do this more often...
This time I had just watched Animenzs absolutely amazing Madoka medley[*], and felt inspired to learn more Madoka songs. But since Im nowhere near good enough to improvise stuff worth uploading, I figured Id record something that I have been practicing for a while, and ended up going with this. Now if only I could figure out how to make myself slow down near the end...
Either way, I hope you guys find it enjoyable. Audio, in case someone asks: https://mrcn.st/t/sisters_noise_yt.flac
[*] https://www.youtube.com/watch?v=4xVyBmkEZX4")
![M2 Asahi Linux bring-up [2022-06-27]](https://i.ytimg.com/vi/SidIJkC5YN0/mqdefault.jpg "M2 Asahi Linux bring-up [2022-06-27]
The M2 is here! Time to make it run Linux.
Website: https://asahilinux.org
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In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
There is currently no set schedule for these streams, so subscribe and click the bell if you want to be notified when they happen.
I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
![Work stream: Writing a hypervisor Pt.12 [2021-05-25]](https://i.ytimg.com/vi/VX5G-fvcG44/mqdefault.jpg "Work stream: Writing a hypervisor Pt.12 [2021-05-25]
Mmiotrace hypervisor, maybe?
Website: https://asahilinux.org
Patreon: https://patreon.com/marcan
GitHub Sponsors: https://github.com/sponsors/marcan
In these streams I show how I work. I may or may not talk, and I may or may not read the chat. If you need to catch my attention, its probably best to ping me on IRC, check out asahilinux.org for details!
There is currently no set schedule for these streams, so subscribe and click the bell if you want to be notified when they happen.
I do not broadcast background music, for copyright reasons and because my music tastes may not match yours. I highly recommend bringing along your own music!")
